A high pressure discharge lamp has a ceramic discharge vessel with two end portions. Sealing members (usually referred to as a ceramic plug) are inserted, respectively, to seal the respective end portions. A through hole is formed in each sealing member. A metal member with a specific electrode system is inserted in the through hole. An ionizable light-emitting material is introduced and sealed in the inner space of the discharge vessel. Known high pressure discharge lamps include high pressure sodium vapor and metal halide lamps, the latter exhibiting more superior color coordination. The lamp can be used under high temperature condition by forming the discharge vessel with a ceramic material.
In such discharge lamp, it is necessary to air-tightly seal between the end portion of the ceramic discharge vessel and a member for supporting an electrode system. The ceramic discharge vessel has a main body with a shape of a tube with two narrow ends, or a barrel, or a straight tube. The discharge vessel is made of, for example, an alumina sintered body. The respective ends of the discharge vessel may be sealed as described, for example, in Japanese patent publication 6-318, 435A. Further, Japanese patent publication 7-176, 296A discloses a method for sealing a metal vapor luminous vessel.